Infrasound occurs at frequencies below the range of human hearing. These signals are of interest because of the signals' ability to propagate long distances with very little attenuation, making them useful for both scientific and military applications (nuclear test ban treaty monitoring in particular). In the past, infrasound microphones have been built with large diaphragms and reference chambers to achieve the desired sensitivity. For many applications, the size of these devices makes them impractical for many applications. Thus, there is a need for sensing devices reduced in size, weight and cost, which are more practical for a wide range of new uses.